Sensor doppler/wavelet processing

Abstract

A method according to an aspect of the invention is for filtering coherent multipulse radar, sonar or lidar returns. The method comprises the steps of separating the returns into mutually orthogonal I & Q components, performing wavelet processing on the I and Q components to generate an I & Q wavelet filter output. The I & Q wavelet filter outputs are data compressed to remove clutter portions. Data compression may be removal of large-amplitude or earliest wavelet responses. An inverse wavelet filtering function is performed on the compressed wavelet filter outputs, to thereby generate edited coherent I & Q components. Doppler filtering, is performed on the edited coherent I and Q components to thereby generate frequency-domain target data in which the minimum discernible target velocity is improved.

1. A method for filtering coherent multipulse radar return signals, said method comprising the steps of:
 separating said return signals into mutually orthogonal I and Q components; 
 performing wavelet processing on said I component to generate an I wavelet filter output; 
 performing wavelet processing on said Q component to generate a Q wavelet filter output; 
 data compressing said I and Q wavelet filter outputs to remove those portions which are most likely to contain clutter to thereby generate data compressed wavelet filter outputs; 
 performing an inverse wavelet filtering function on the compressed wavelet filter outputs, to thereby generate edited coherent I and Q components; 
 Doppler filtering said edited coherent I and Q components to thereby generate frequency-domain target data in which the minimum discernible target velocity is improved. 
 
   
   
     2. A method according to  claim 1 , wherein said step of data compressing said I and Q wavelet filter outputs comprises the step of removing those portions of said I and Q wavelet filter outputs which have the largest amplitudes. 
   
   
     3. A method according to  claim 1 , wherein said step of data compressing said I and Q wavelet filter outputs comprises the step of removing those I and Q wavelet filter outputs which occur earliest in the stream of wavelet responses. 
   
   
     4. A method according to  claim 1 , further comprising the step of Doppler filtering said mutually orthogonal I and Q components into frequency bins having frequencies above the frequencies associated with said minimum discernible target velocity.